Results for “taxon”

There is some confusion regarding the taxonomy of this species and its congener L. stappersi. L. stappersi was originally regarded as a subspecies of perspicax but is now considered a distinct species. It is not often seen in the hobby....

This species is frequently mistaken for the similar-looking congener M. spechti Schreitmüller 1936, which is easily-identified by the absence of reddish pigmentation in the dorsal, anal, and caudal fins. There has been some debate as to whether these two represent the same taxon, however, with Winstanley and Clements (2008) proposing that M. erythropterus be considered a synonym of M. spechti because they were unable to separate the two species by morphological characters, and specimens with red pigmentation on the unpaired fins were coll...

Although it is included in the genus Metzia this grouping remains somewhat unresolved in terms of taxonomy and it may contain more than a single genetic lineage. For example, members share a number of characters with the genera Ischikauia Jordan and Snyder 1900, Hemiculterella Warpachowski 1887, and several species of Anabarilius Cockerell 1923, including a bipartite gas bladder, a non-spinous dorsal-fin ray, and a sharp ventral keel between the pelvic-fin insertion and anus.

A rather rare fish in the UK hobby. It occasionally shows up as a contaminant among imports of more popular species. The taxonomic status of all species in the genus Moenkhausia is currently Incertae Sedis, meaning uncertain. The genus is currently used as something of a catch-all for a large number of small characin species. Most experts agree that a full revision is required, with the likely outcome that many of these will be placed into new or different genera....

This species is one of a handful that closely resemble the popular red-eyed tetra, M. sanctaefilomenae. This species is seen much less often in the hobby than its relative however and is also known as the glassy tetra. The taxonomic status of all species in the genus Moenkhausia is currently Incertae Sedis, meaning uncertain. The genus is currently used as something of a catch-all for a large number of small characin species. Most experts agree that a full revision is required, with the likel...

This species is something of an "ugly duckling", as it's usually sold as a fairly bland looking, silvery juvenile. Given time and a good diet it develops into a magnificent fish as an adult, that really does sparkle like a diamond. A big shoal of these in a planted tank looks stunning. The taxonomic status of all species in the genus Moenkhausia is currently Incertae Sedis, meaning uncertain. The genus is currently used as something of a catch-all for a large number of small ch...

This species can be found swimming in most dealers' tanks and is one of the best choices for the newcomer to fishkeeping. All the fish sold in the trade have been captive bred and as such are unfussy regarding water chemistry and diet. The taxonomic status of all species in the genus Moenkhausia is currently Incertae Sedis, meaning uncertain. The genus is currently used as something of a catch-all for a large number of small characin species. Most experts agree that a full revision is re...

This infrequently seen (in the trade) species is also known as the two spot glass catfish, for fairly obvious reasons. It is more than likely that a number of separate species are currently considered within this one, as there are clear morphological differences between populations. Pending a taxonomic revision, these currently all remain classified as O.bimaculatus. This would also seem to explain the apparent toleration of the fish to wildly different water chemistry. Xanthic and albino forms ...

This species continues to be mislabelled as O. melastigma, a name currently considered invalid by the majority of recent workers, or O. javanicus, a valid but distinct taxon. Roberts (1998) demonstrated that MClelland's description of Aplocheilus melastigmus, later renamed O. melastigma, does not correspond with any known Oryzias species from the Indian subcontinent or Myanmar since it's said to have a dark spot in the dorsal-fin and an excessively slim body, among other anomalies.

For aquarists perhaps more useful are the subtle differences in colour pattern with P. simulans differing from both P. innesi and P. axelrodi in possessing a greener (vs. bluer) lateral stripe which covers more (vs. less) of the eye/head and extends to the caudal-fin base (vs. terminating anterior to caudal-fin base), a lesser (vs. greater) amount of relatively duller (vs. brighter) red pigmentation on the flanks. The taxonomic history of all three species is complicated with earlier authors such as Géry (1960, 1977) ten...

This species is poorly-known in the aquarium hobby and has a confusing taxonomic history having been considered both synonymous with or a subspecies of the congener P. ticto in the past. It can be distinguished from other members of the genus by the following combination of characters: lateral line complete with 27 scales (following Day); body with two dark blotches; anterior spot one scale row below lateral line; dorsal-fin with rows of spots.

There are currently 32 genera and over 80 species included in the family Pimelodidae (including Pimelodus), making it the second largest and one of the most diverse amongst catfish. Most experts agree however, that a full systematic revision of the family is needed, as little information about the phylogenetic (evolutionary relatedness) relationships between the various genera exists. Taxonomy information at the species level is also basic at best. It's therefore likely that at least some o...

There are currently 32 genera included in the family Pimelodidae (including Pimelodus), making it the second largest and one of the most diverse amongst catfish. However most experts agree that a full systematic revision of the family is needed, as little information about the phylogenetic (evolutionary relatedness) relationships between the various genera exists. Taxonomy information at the species level is also basic at best. It's therefore likely that at least some of the Pimelodids will...

There are currently 32 genera and over 80 species included in the family Pimelodidae (including Pimelodus), making it the second largest and one of the most diverse amongst catfish. However most experts agree that a full systematic revision of the family is needed, as little information about the phylogenetic (evolutionary relatedness) relationships between the various genera exists. Taxonomy information at the species level is also basic at best. It's therefore likely that at least some of...

This stunning fish is one of the more sought after rays in the hobby. Taxonomically it remains unclear whether it is a geographical variant of P. leopoldi or a distinct species. It has a smaller adult size and both pups (see section above) and adults exhibit different patterning than it's relative. In P. leopoldi the light spotted markings tend to be quite large, spaced out and do not extend to the edge of the disc. In P14 they are typically much smaller, more randomly distributed and prese...

This species has a confusing taxonomic past. There are currently 3 subspecies, Pseudotropheus tropheops tropheops, P. t. romandi and P. t. gracilior. P. macrophthalmus and P. microstoma were also once considered as subspecies of tropheops, but are now classed as distinct species. Furthermore, it is likely that the current subspecies and their various colour forms (of which there are many) will be themselves reclassifed into the currently invalid genus Tropheops! Incidentally, none of the subspec...

This species has a chaotic taxonomic history with certain issues still to be resolved. While the name P. mahecola was misapplied to members of the genus Dawkinsia for over a century the fish itself has been widely misidentified as the congener P. amphibius (Valenciennes 1842). Its identity was partially resolved by Pethiyagoda and Kottelat (2005b) who demonstrated that though valid P. mahecola is not a Dawkinsia spp. but rather a smaller, relatively plain species with a single dark blotc...

One of the most common of the numerous species sold as 'whiptail catfish', R. eigenmanni is an excellent species for the newcomer to Loricariids or catfish breeding. It's certainly not the most active species, but when settled and housed with the correct kind of tankmates, it is by no means shy either. It does have a bit of a confusing taxonomic past, though. Whilst currently considered a member of Rineloricaria, it was first decribed as a species of Loricaria, before being mov...

A bright blue variant normally referred to as 'electric blue Jack Dempsey' or simply 'EBJD' is of unclear origin but it appears to be an ornamental strain fixed from a natural mutation. Care is as per the natural form although the blue fish tend to remain smaller and some reports suggest them to be less aggressive. R. octofasciata has a confusing taxono...

S. maculatus is one of the better choices for aquarists new to this group of fishes. It grows to a manageable size, is relatively hardy, attractive and usually quite inexpensive. It's sometimes referred to by the alternative vernacular names "gold piranha" or "golden mac" in the hobby. There are in excess of 30 described species of Serrasalmus many of which appear superficially similar and have confusing taxonomic histories. S. maculatus and S. spilopleura have often ...